In the Oct. issue of SCC they talk a lot about japanese tuners stitch welding the seams of the chassis for increased rigidity. Has anyone stateside done this? Does it make a big difference? Does it have negative effects of ride quality (I would imagine so), and if so, how badly? For those of us with access to the tools, it seems like a cheap way to improve upon the car assuming that it doesn't ride like *** afterward.

 

I think it would be a good move, but it sure isn't cheap or easy. You have to take everything or almost everything off the chassis and repaint it when you finish. Best for cars you have apart anyway to build from the ground up.

-Max

 

I've thought about doing this for a long time. Sooner or later, I'm going to give it a try. There are several different methods that the tuners use. Stich welding is just one of them, I'm not sure which would be better then the other, etc...
Anyone else have any other insight???

 

A really big article about stitch welding on FD's specifically in the September Options 2 magazine. Unfortunately, its 100% japanese So i cant make anything out. It looks like they will even go so far as to stitch weld closer to the actual panels/joints, and then chop off the remaining "flash" above it in an effort to reduce weight. Heres a couple of pics from the article, wish I had a scanner..





Now that is one stripped FD..

 

Oh good, instructions!

 

wow, that's some gorgeous chassis work.

 

Nice sock! What exactly is stitch welding and what is it supposed to do? This is the first I have ever heard of it.

 

if you ask me... that looks like a mig welder in that guys hand in the pic, not a sewing machine... if you want to get technical that is...

 

ttpowered, as quoted from SCC "Stitch welding involves running beads along the seams in a chassis, and greatly increases chassis rigidity. Such chassis preparation is common in drag, road and rally racing."

 

stich welding is basically making little welds all along the main chasis joints of the car so you improve rigidity. you kinda make your multiple section chasis into a tubeframe (in theory) from what i hear it makes quite the difference but i can imagine how stiff the ride would be after that kind of thing.

 

It's also called Seam welding by some. I'm probably going to stitch weld my rally car (at least in strategic places). You do have to have the car totally stripped down, and a cage should be in it, otherwise you might tweak the whole chassis.

but yeah, basically, auto manufacturers use this glue like substance to sandwhich together pieces of the body. Well, that glue stretches and bends, So what stitch welding does, is make all that rigid. You are basically putting down a 1 inch weld every 2-3 inches everywhere you can.

It's very important in rally racing, where you will end up tearing apart your chassis if you DON'T stitch weld. In Road racing, it's more for to stiffen the chassis for more predictable suspension geometry.

 

I've cut apart a couple FDs and haven't seen any "glue". The chassis is spot welded together, one FD had been hit right next to a seam without impacting the seam itself. 5 spot welds in a row were separated from the panel they were intended to be welded to. They were never welded in the first place, there was paint underneath the weld. Seam welding helps fix these production "errors" and also adds strength.

Jeff

 

I know a REALLY good welder that can do anything you can think of. He can also fabricate just about anything with metal. Fair pricing and amazing work...can't get any better.

He's in Florida but he flys to jobs everywhere in the world.
If you guys need anything shoot a pm over to snooks inbox.

Snook